<template>
  <div>
    <table border="1" width="700" style="border-collapse: collapse">
      <caption>
        购物车
      </caption>
      <thead>
        <tr>
          <th><input type="checkbox" v-model="all" /> <span>全选</span></th>
          <th>名称</th>
          <th>价格</th>
          <th>数量</th>
          <th>总价</th>
          <th>操作</th>
        </tr>
      </thead>
      <tbody>
        <MyTag
          v-for="(item, index) in goodList"
          :key="index"
          :item="item"
          :index="index"
          @change-num="changeNum"
          @checked-event="goodList[$event].checked = !goodList[$event].checked"
          @del="goodList.splice(index, 1)"
        ></MyTag>
      </tbody>
      <tfoot>
        <tr>
          <td>合计:{{allPrice}}</td>
          <td colspan="5"></td>
        </tr>
      </tfoot>
    </table>
  </div>
</template>

<script>
import MyTag from "./components/MyTag.vue";
export default {
  data() {
    return {
      goodList: [
        {
          name: "诸葛亮",
          price: 1000,
          num: 1,
          checked: false,
        },
        {
          name: "蔡文姬",
          price: 1500,
          num: 1,
          checked: false,
        },
        {
          name: "妲己",
          price: 2000,
          num: 1,
          checked: false,
        },
        {
          name: "鲁班",
          price: 2200,
          num: 1,
          checked: false,
        },
      ],
    };
  },
  components: {
    MyTag,
  },
  methods: {
    changeNum(now, index) {
      this.goodList[index].num = now;
    },
  },
  computed: {
    all: {
      get() {
        if (this.goodList.length === 0) {
          return false;
        } else {
          return this.goodList.every((item) => item.checked === true);
        }
      },
      set(value) {
        this.goodList.forEach((item) => (item.checked = value));
      },
    },
  allPrice(){
      const arr = this.goodList.filter((item)=>item.checked===true)
      return arr.reduce((sum,item)=>sum+item.price*item.num,0)
  }    
  
  },
};
</script>

<style></style>
